A wavelength of a light source used in an exposure apparatus becomes shorter as a semiconductor device is shrunk and an exposure apparatus (EUV exposure apparatus) which uses extreme ultraviolet light (hereinafter, also referred to as EUV light) with a wavelength of approximately 100 nm or shorter is increasingly applied to the semiconductor device. The EUV light has a property of being attenuated in an atmosphere and less easily transmitted through a material such as glass used as a mask of a conventional exposure apparatus. Therefore, EUV exposure is performed in general by using a reflective mask provided with a multilayer film such as Mo and Si in a vacuum chamber.
Since the EUV exposure is performed in the vacuum chamber in this manner, it is difficult to apply a method of holding an outer peripheral portion of the mask by a vacuum absorption chuck used in the conventional exposure apparatus as a mechanism to hold the mask. Therefore, a method of holding a rear surface side of the mask by an electrostatic chuck is used in general.
An electrostatic chuck holding mechanism has a structure in which an electrode layer is formed on a base body surface and a plurality of convex portions in contact with the mask rear surface is arranged on the electrode layer in a two-dimensional manner. The convex portions are arranged so as to be also in contact with the rear surface included in a pattern area of the mask. Therefore, a contact area between the electrostatic chuck holding mechanism and the mask rear surface becomes larger than that in a case of holding by the conventional vacuum absorption chuck. According to this, possibility that a particle adheres to the mask rear surface or the electrostatic chuck becomes higher. When the mask is held by using the electrostatic chuck holding mechanism in a state in which the particle adheres to the mask rear surface, flat mask clamping cannot be realized and there is a case in which an exposure pattern is not normally formed.
Therefore, an exposure process is performed after performing mask rear surface inspection and allowing the particle of a predetermined size or a predetermined number of particles to adhere to the mask rear surface.